Introduction

Line bending is a process used to bend thermoplastics in a straight line.

The line bending process involves heating a thermoplastic sheet over a strip heater until it becomes soft and then bending it to any desired angle.

The plastic sheet is then held still until it cools and stays in the bent shape.

  
Acrylic sheet bent by line bending
Flow chart of the stages of the line bending process.
 

Line bending in detail

Animation of the line bending process

Line benders / strip heaters

Jigs used with line bending

Thermoplastics used for line bending

The table of plastic processing temperatures below shows the temperatures at which thermoplastic sheets may be bent using the line bending process. The figures in the "Orientation" column give the optimal temperature at which the polymers may be bent.

Plastic Processing Temperatures In Degrees Celsius

Polymer

Abbr.

Lower processing
Orientation

Upper Temperature
Acrylonitrile-butadiene-styrene
ABS
127
138
204
Polystyrene
PS
127
135
182
Polyethylene, high density
HDPE
127
132
221
Polypropylene
PP
132
138
193
Polymethylmethacrylate (Acrylic)
PMMA
149
163
218
Polycarbonate
PC
168
177
204

Source: MAAC Machinery Corporation, www.maaacmachinery.com

Plastic processing temperatures in more detail
 
 
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Copyright Laszlo Lipot.